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Related to Pennsylvanian period: Permian period, Mississippian Period, Carboniferous period, Upper Carboniferous, Upper Pennsylvanian
Pennsylvanian period:see Carboniferous periodCarboniferous period
, fifth period of the Paleozoic era of geologic time (see Geologic Timescale, table), from 350 to 290 million years ago. Historical Geology of the Period
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